Former special counsel Robert Mueller forcefully pushed back on a Republican congressman after it was suggested that he selected his staff based on their political affiliations.

At a House Judiciary hearing on Wednesday, Rep. Kelly Armstrong (R-ND) appeared to get under the former special counsel’s skin by asking about attorneys on his staff.

“You must be aware by now that six of your lawyers donated $12,000 directly to Hillary Clinton,” Armstrong charged. “I’m not even talking about the $49,000 they donated to other Democrats. Just the donations to the opponent who was the target of your investigation?”

“We strove to hire individuals who could do the job,” Mueller shot back “I’ve been in this business for almost 25 years. In those 25 years, I’ve not had occasion once to ask about somebody’s political affiliation.”

“It is not done,” he added. “What I care about is the capability of the individual to do the job and do the job seriously and quickly and with integrity.”